INVESTIGATION OF THE EFFECT OF DOUBLE RINGS INFILTROMETER DIMENSION ON INFILTRATION RATE

Overestimation of vertical infiltration rate as a result of diverges laterally flow is a major problem in the use of infiltrometers. Although, the double-ring infiltrometer minimizes the error associated with lateral divergence, no specific dimension has been given for its usage. This report gives an investigation of the effect of dimension of double rings infiltrometer on the infiltration rate at the University of Agriculture Abeokuta. This study was conducted during the dry season and wet season on a vegetated land in the year 2011. Three pairs of double rings infiltrometer were used comprising of 30:60, 15:30 and 7.5:15 cm diameter rings. The 15:30 dimension offered the best accuracy with significant (p = 0.01) coefficient of determination of infiltration, followed by the 7.5:15 cm rings and lastly the 30:60 cm ring. The relative reliability of each dimension in terms of accuracy of measured infiltration data utilized was assessed by the mean of result of infiltration rate from the three pairs of double rings infiltrometer.